Be- and Mg-Based Electron and Anion Sponges.

Area of Science:

• Computational Chemistry
• Quantum Chemistry
• Materials Science

Background:

• Electron-deficient substituents are crucial for developing novel materials with unique electronic properties.
• Cyclopropane derivatives have shown potential in various chemical applications, but their electronic characteristics are not fully explored.
• Understanding electron and anion affinities is key to designing molecules for electron capture or anion binding.

Purpose of the Study:

• To investigate the electron and anion affinities of beryllium (Be) and magnesium (Mg) derivatives of cyclopropane.
• To evaluate the potential of these compounds as electron acceptors or anion sponges.
• To compare the electronic properties of Be- and Mg-containing cyclopropane derivatives.

Main Methods:

• Employed high-level ab initio calculations using the G4(MP2) method.
• Calculated electron affinities (EAs) and anion affinities (AAs) for various -BeX and -MgX (X=CH3, F, Cl, CN) substituted cyclopropane systems.
• Compared the calculated affinities with existing data for neutral closed-shell systems and known anion sponges.

Main Results:

• Be and Mg cyclopropane derivatives exhibit very large electron and anion affinities.
• These affinities are among the highest reported for neutral closed-shell molecules, exceeding those of 1,8-diBeX-naphthalene derivatives.
• Unexpectedly, Mg-containing compounds demonstrate higher intrinsic anion affinity than their Be-containing analogs.

Conclusions:

• Beryllium and magnesium cyclopropane derivatives are potent electron and anion acceptors.
• These compounds represent a new class of highly effective anion sponges.
• The superior anion affinity of Mg derivatives suggests novel design strategies for anion-binding materials.